Method of controlling fluid flow

This application claims the benefit of U.S. Provisional Application 63/397,020, filed Aug. 11, 2022, which is incorporated herein by reference in its entirety.

Mass flow control has been one of the key technologies used in semiconductor chip fabrication. Apparatuses for controlling mass flow are important for delivering known flow rates of process gases and liquids for semiconductor fabrication and other industrial processes. Such devices are used to measure and accurately control the flow of fluids for a variety of applications. In a given fabrication tool, processing systems of the fabrication tool incorporates a variety of apparatuses for controlling flow to deliver a variety of liquids and gases. As a result, efficient gas and liquid handling is essential to modern semiconductor fabrication equipment.

As the technology of chip fabrication has improved, so has the demand on the apparatuses for controlling flow. Semiconductor fabrication processes increasingly require increased performance, a greater range of flow capability, more process gases and liquids, and more compact installation of the necessary equipment. Improved gas and liquid handling for a variety of flow apparatuses is desirable to deliver enhanced performance in reduced space and at a reduced cost while avoiding undesired chemical interactions.

The present technology is directed to methods of controlling fluid flows in systems for processing articles such as semiconductors. In other embodiments, the present technology is directed to systems for controlling flows of process fluids. In yet other embodiments, the present technology is directed to systems for transporting process fluids. In other embodiments, the present technology is directed to apparatuses for controlling flow of process fluids. The present systems, methods, and apparatuses may be used in a wide range of processes such as semiconductor chip fabrication, solar panel fabrication, etc.

In one implementation, the invention is a method of controlling fluid flow. In a first step, a processing system is provided. The processing system comprises a first fluid supply configured to supply a first process fluid and a second fluid supply configured to supply a second process fluid. The first fluid supply is fluidly coupled to an inlet of a first apparatus for controlling flow and the second fluid supply fluidly coupled to a second apparatus for controlling flow. In a second step, the first process fluid is delivered to a processing chamber fluidly coupled to an outlet of the first apparatus for controlling flow. In a third step, the first process fluid is vented to a vent manifold fluidly coupled to a bleed port of the first apparatus for controlling flow at a first flow rate which is less than a first threshold.

In another implementation, the invention is a method of controlling fluid flow. In a first step, a processing system is provided. The processing system comprises a first fluid supply configured to supply a first process fluid and a second fluid supply configured to supply a second process fluid. The first fluid supply is fluidly coupled to an inlet of a first apparatus for controlling flow and the second fluid supply fluidly coupled to a second apparatus for controlling flow. In a second step, the first process fluid is delivered to a processing chamber fluidly coupled to an outlet of the first apparatus for controlling flow. In a third step, the first process fluid is vented to a vent manifold fluidly coupled to a bleed port of the first apparatus for controlling flow at a first flow rate and simultaneously venting the second process fluid to the vent manifold fluidly coupled to a bleed port of the second apparatus for controlling flow at a second flow rate to control a concentration of the first process fluid within the vent manifold below a second threshold.

In one implementation, the invention is a method of controlling fluid flow. In a first step, a processing system is provided. The processing system comprises a first fluid supply configured to supply a first process fluid and a second fluid supply configured to supply a second process fluid. The first fluid supply is fluidly coupled to an inlet of a first apparatus for controlling flow and the second fluid supply fluidly coupled to a second apparatus for controlling flow. In a second step, the first process fluid is vented to a vent manifold fluidly coupled to a bleed port of the first apparatus for controlling flow at a first flow rate, a concentration of the first process fluid within the vent manifold being below a second threshold. In a third step, the first process fluid is delivered to a processing chamber fluidly coupled to an outlet of the first apparatus for controlling flow.

Further areas of applicability of the present technology will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred implementation, are intended for purposes of illustration only and are not intended to limit the scope of the technology.

The description of illustrative embodiments according to principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “left,” “right,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation unless explicitly indicated as such. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the invention are illustrated by reference to the preferred embodiments. Accordingly, the invention expressly should not be limited to such preferred embodiments illustrating some possible non-limiting combinations of features that may exist alone or in other combinations of features; the scope of the invention being defined by the claims appended hereto.

The present invention is directed to systems for processing articles, these systems having apparatuses for controlling fluid flow. In some embodiments, the apparatus may function as a mass flow controller to deliver a known mass flow of gas or liquid to a semiconductor or similar process. Semiconductor fabrication is one industry which demands high performance in control of fluid flows. As semiconductor fabrication techniques have advanced, customers have recognized the need for flow control devices with increased accuracy and repeatability in the mass of the delivered fluid flows. In addition, flow control devices have increased in complexity, utilizing more sophisticated arrangements that require delivery and removal of a variety of process fluids. The present systems enable rapid assembly and maintenance of systems for processing articles by utilizing standardized manifold configurations.

1 FIG. 1000 1000 100 1300 100 1010 1010 100 1010 100 100 1010 1010 1010 shows a schematic of an exemplary processing systemfor processing articles. The processing systemmay utilize a plurality of apparatus for controlling flowfluidly coupled to a processing chamber. Each of the plurality of apparatus for controlling flowhas a fluid supplyfluidly coupled thereto, each of the fluid suppliessuppling a process fluid to their respective apparatuses for controlling flow. Optionally, a plurality of fluid suppliesmay be fluidly coupled to a single apparatus for controlling flowor a plurality of apparatuses for controlling flowmay be fluidly coupled to a single fluid supply. Each of the fluid suppliesmay deliver a different process fluid or a portion of the fluid suppliesmay deliver a single process fluid.

100 1300 400 1300 1100 100 1300 100 1300 1300 100 100 The plurality of apparatus for controlling floware used to supply one or more different process fluids to the processing chambervia an outlet manifold. Articles such as semiconductors may be processed within the processing chamber. A valveisolates the apparatuses for controlling flowfrom the processing chamber, enabling the apparatuses for controlling flowto be selectively connected or isolated from the processing chamber. The processing chambermay contain one or more applicators to apply process fluids delivered by the plurality of apparatus for controlling flow, enabling selective or diffuse distribution of the fluid supplied by the plurality of apparatus for controlling flow.

1000 1200 1300 1100 100 100 100 500 500 1200 1100 100 1100 100 1100 1000 In addition, the processing systemmay further comprise a vacuum sourcewhich is isolated from the processing chamberby a valveto enable evacuation of process fluids or facilitate purging one or more of the apparatus for controlling flowto enable switching between process fluids in the same apparatus for controlling flow. Each of the apparatuses for controlling flowmay have a separate bleed port which is coupled to a vent manifold, the vent manifoldconnected to the vacuum sourcevia a valve. Optionally, the apparatuses for controlling flowmay be mass flow controllers, flow splitters, or any other device which controls the flow of a process fluid in a processing system. Furthermore, valvesmay be integrated into the apparatus for controlling flowif so desired. In some implementations this may eliminate the need for certain other valvesin the processing system.

1000 Processes that may be performed in the processing systemmay include wet cleaning, photolithography, ion implantation, dry etching, atomic layer etching, wet etching, plasma ashing, rapid thermal annealing, furnace annealing, thermal oxidation, chemical vapor deposition, atomic layer deposition, physical vapor deposition, molecular beam epitaxy, laser lift-off, electrochemical deposition, chemical-mechanical polishing, wafer testing, or any other process utilizing controlled volumes of a process fluid.

2 FIG. 101 100 1000 101 1010 104 104 120 120 120 106 120 shows a schematic of an exemplary mass flow controller, which is one type of apparatus for controlling flowthat may be utilized in the processing system. The mass flow controllerhas a fluid supplyof a process fluid fluidly coupled to an inlet. The inletis fluidly coupled to a proportional valvewhich is capable of varying the mass and volume of process fluid flowing through the proportional valve. The proportional valvemeters the mass flow of process fluid which passes to a P1 volume. The proportional valveis capable of providing proportional control of the process fluid such that it need not be fully open or closed, but instead may have intermediate states to permit control of the mass flow rate of process fluid.

106 120 106 101 120 160 130 106 106 150 160 120 106 160 150 120 160 110 101 110 1100 1300 160 150 110 150 160 110 150 160 The P1 volumeis fluidly coupled to the proportional valve, the P1 volumebeing the sum of all the volume within the mass flow controllerbetween the proportional valveand a flow restrictor. A pressure transduceris fluidly coupled to the P1 volumeto enable measurement of the pressure within the P1 volume. A shutoff valveis located between the flow restrictorand the proportional valveand may be used to completely halt flow of the process fluid out of the P1 volume. Optionally, the flow restrictormay be located between the shutoff valveand the proportional valvein an alternate configuration. The flow restrictoris fluidly coupled to an outletof the mass flow controller. In the processing system, the outletis fluidly coupled to a valveor directly to the processing chamber. In the present embodiment, the flow restrictoris located between the shutoff valveand the outlet. In an alternate embodiment, the shutoff valveis located between the flow restrictorand the outlet. Thus, the arrangement of the shutoff valveand the flow restrictormay be reversed.

180 106 190 180 180 160 190 180 190 160 180 180 180 Finally, a bleed valveis coupled to the P1 volumeand to a bleed port. In the present example, the bleed valveis a proportional valve. The bleed valvemay also be an on/off valve or any other type of valve suitable for controlling fluid flow. Optionally, a second flow restrictormay be incorporated between the P1 volume and the bleed port. A proportional valve, if used as the bleed valve, enables control over a rate of fluid flow through the bleed port. A characterized restrictormay aid in improving control over the rate of fluid flow, regardless of whether the bleed valveis a proportional valve or an on/off valve. Preferably, the rate of fluid flow through the bleed valveis characterized so that the flow rate can be estimated for a given state of the bleed valve.

150 100 150 150 150 Internal to the first shutoff valveis a valve seat and a closure member. When the apparatusis delivering process fluid, the first shutoff valveis in an open state, such that the valve seat and the closure member are not in contact. This permits flow of the process fluid and provides a negligible restriction to fluid flow. When the first shutoff valveis in a closed state the closure member and the valve seat are biased into contact by a spring, stopping the flow of process fluid through the first shutoff valve.

160 120 160 160 160 160 The flow restrictoris used, in combination with the proportional valve, to meter flow of the process fluid. In most embodiments, the flow restrictorprovides a known restriction to fluid flow. The first characterized flow restrictormay be selected to have a specific flow impedance so as to deliver a desired range of mass flow rates of a given process fluid. The flow restrictorhas a greater resistance to flow than the passages upstream and downstream of the flow restrictor.

101 160 150 160 160 100 101 Optionally, the mass flow controllercomprises one or more P2 pressure transducers downstream of the flow restrictorand the shutoff valve. The P2 pressure transducer is used to measure the pressure differential across the flow restrictor. In some embodiments, the P2 pressure downstream of the flow restrictormay be obtained from another apparatusconnected to the processing chamber, with the readings communicated to the mass flow controller.

101 101 106 120 130 150 180 Optionally, temperature sensors may be employed to further enhance the accuracy of the mass flow controller. They may be mounted in the base of the mass flow controllernear the P1 volume. Additional temperature sensors may be employed in a variety of locations, including adjacent the proportional valve, the pressure transducer, the shutoff valve, and the bleed valve.

3 FIG. 1 FIG. 250 1000 260 200 260 100 1000 260 262 264 266 268 270 272 272 262 260 200 270 260 100 100 260 260 200 260 276 Turning to, a block diagram illustrates a controllerfor the processing systemof. This block diagram shows an apparatus controllerand a system controller. The apparatus controllerprovides all control functions for an apparatus for controlling flowwithin the processing system. The apparatus controllerhas a communication interface, a proportional valve controller, a pressure transducer interface, an on/off valve controller, a temperature sensor interface, a processor, and memory. The communication interfaceis configured to provide a communications link between the apparatus controllerand the system controller. Optionally, the temperature sensor interfacemay be omitted if the additional accuracy provided by a temperature sensor is not required. Optionally, a single apparatus controllermay operate a plurality of apparatuses for controlling flowor each apparatus for controlling flowmay have a dedicated apparatus controller, each of the apparatus controllerscommunicating with the system controllerand other apparatus controllersvia a communications bus.

200 210 222 224 200 210 200 276 276 262 260 276 200 200 200 200 100 200 100 276 276 200 260 The system controllerhas a corresponding communication interface, a processor, and memory. The system controllercoordinates all high-level functions necessary to perform the desired process. The communication interfaceof the system controllersends and receives commands through the communications bus. The communications busconnects to the communication interfaceof the apparatus controller. The communications busmay connect the system controllerto a single apparatus controller, or it may connect to a plurality of apparatus controllers, each apparatus controlleroperating a distinct apparatus for controlling flow. Not all apparatus controllersneed control an apparatus for controlling gas flow. Instead, other types of process equipment may also be controlled. Furthermore, there may be a plurality of communications busesto connect all the devices required to perform the desired process. In other implementations, the communications busmay be substituted with a plurality of direct communications links between individual controllers,.

4 FIG. 100 300 100 100 101 100 101 101 300 Turning to, a perspective view of a plurality of apparatuses for controlling flowand a manifold systemare shown. As can be seen, six apparatusesare provided in a row. In this example, each of the apparatusesare mass flow controllers, but each of the apparatusescould be different devices. Furthermore, not every mass flow controllerneed be identical. Some may support different fluids, different ranges of flow capability, or any other variation necessary to implement the desired process. As can be seen, the mass flow controllersare mounted to the manifold system.

5 13 FIGS.- 101 301 300 301 101 100 300 show a single mass flow controllerin greater detail, along with a portionof the manifold system. The portionprovides the necessary attachment features to mount the mass flow controlleror other apparatusesin a standardized configuration. The manifold systemcomprises both the vacuum and outlet manifolds.

13 FIG. 5 12 FIGS.- 101 301 300 101 103 105 107 103 103 103 104 110 104 110 104 102 104 110 104 110 101 104 110 101 Turning to, a cross-section of the mass flow controllerand the portionof the manifold systemare shown. The mass flow controllercomprises a baseformed of a first portionand a second portion. In some embodiments the baseis unitary and monolithic, while in other instances the basemay be formed of more than two portions. The basecomprises an inletand an outlet, a flow path extending from the inletto the outlet. The inletis fluidly coupled to a fluid supplyas discussed above. Process fluids flow from the inletto the outletalong the flow path, the inletbeing referred to as upstream and the outletbeing referred to as downstream, as this is the ordinary direction for fluid flow during operation of the mass flow controller. Both the inletand the outletlie in a plane M-M which extends through the center of the mass flow controlleras shown in.

104 151 151 101 151 101 151 151 The inletis fluidly coupled to an inlet control valve, the inlet control valveserving to control the flow of fluid into the mass flow controller. The primary function of the inlet control valveis to provide guaranteed shutoff of the mass flow controllerfor maintenance, service, calibration, etc. The inlet control valvemay be manually or automatically operated. In some embodiments, the inlet control valvemay be omitted.

151 120 120 122 121 120 120 150 160 150 160 120 160 106 106 120 160 Fluid flows from the inlet control valveto a proportional valve. The proportional valvecomprises the valve seatand a closure member. The proportional valve is configured to transition from a closed state to an open state as well as any intermediate position between the open and the closed states. This allows a variable volumetric flow rate of gas or liquid to pass the proportional valve. Downstream of the proportional valveis a shutoff valveand a characterized restrictor. As discussed above, the shutoff valvemay be upstream or downstream of the characterized restrictor. In this embodiment, the volume between the proportional valveand the characterized restrictoris referred to as a P1 volume. The P1 volumecomprises all volume in the flow path between the valve seat of the proportional valveand the characterized restrictor.

180 130 106 120 160 180 130 106 180 106 190 190 500 A bleed valveand a P1 pressure transducerare fluidly coupled to the P1 volumebetween the proportional valveand the characterized restrictor. The bleed valvecomprises a closure member and a valve seat. The P1 pressure transducermeasures the pressure of the fluid in the P1 volume. The bleed valveis configured to vent fluid from the P1 volumeto a bleed port. The bleed portis connected to the vent manifoldto dispose of process fluids.

160 150 110 160 106 111 111 160 110 111 132 132 111 160 160 130 132 The characterized restrictoris located downstream of the shutoff valveand upstream of the outletas discussed above. The characterized restrictoris configured such that it provides a restriction to fluid flow to provide a pressure differential between the P1 volumeand a P2 volume. The P2 volumecomprises the volume of the flow path between the characterized restrictorand the outlet. The P2 volumeis fluidly coupled to a P2 pressure transducer, the P2 pressure transducermeasuring the pressure of the fluid in the P2 volume. The restriction to fluid flow of the characterized restrictormay also be referred to as a flow impedance, the flow impedance being sufficiently high that the pressure drop across the characterized restrictorcan be measured using the P1 and P2 pressure transducers,.

160 150 160 150 150 130 132 131 130 132 109 106 111 109 106 111 In some embodiments, the characterized restrictormay be upstream of the shutoff valve. In some embodiments, the characterized restrictormay be at least partially located within the shutoff valve. In yet other embodiments, the shutoff valvemay be omitted. The P1 and P2 pressure transducers,may also be omitted in certain embodiments. In yet other embodiments, one or more of the P0, P1, and P2 pressure transducers,,may be differential pressure sensors, and may be fluidly coupled to more than one of the P0, P1, and P2 volumes,,to permit differential pressure measurement between the P0, P1, and P2 volumes,,.

180 190 180 181 180 190 181 112 112 103 114 190 110 114 112 112 101 301 300 Returning to the bleed valveand the bleed port, it can be seen that the bleed valvecontrols flow through a bleed passagethat connects the bleed valveto the bleed port. This bleed passagemay take any required path to reach a mounting portion. The mounting portionforms a portion of the baseand has a surfacecomprising the bleed portand the outlet. In a preferred embodiment, the surfaceof the mounting portionis planar. The mounting portionenables connection of the mass flow controllerto the portionof the manifold system.

301 300 501 500 401 400 301 300 310 310 112 101 310 101 112 101 310 110 190 500 400 114 112 190 110 112 310 The portionof the manifold systemcomprises a portionof the vent manifoldand a portionof the outlet manifold. The portionof the manifold systemfurther comprises a mounting substrate. The mounting substrateprovides the mechanical connection for the mounting portionof the mass flow controller. The mounting substrateprovides both structural strength and rigidity to the mass flow controllerand ensures robust fluid connection between the two components. The mounting portionof the mass flow controlleris configured to engage the mounting substrateto fluidly couple the outletand the bleed portto the vent manifoldand the outlet manifold. The surfaceof the mounting portionmay incorporate features necessary to ensure that the bleed portand outletcan be adequately sealed to ensure liquid and/or gas tight connections between the mounting portionand the mounting substrate. These features may include recesses or any other feature necessary to provide room for sealing features, seals, or other components that provide a fluid-tight connection.

14 FIG. 2000 2000 1000 1010 1010 2000 1011 1011 1011 1010 1011 1010 1011 1010 1011 1010 Turning to, an exemplary processing systemis shown. The processing systemis similar to the processing systemexcept as discussed herein. The processing system comprises an inert fluid supplywhich supplies a process fluid which is inert. This may be an inert liquid or an inert gas. Examples may include inert gases such as nitrogen, argon, helium, or any of the noble gases. Thus, the inert fluid supplysupplies a fluid which is chemically inert. The processing systemalso comprises two reactive fluid supplies. Each of the reactive fluid suppliessupply reactive fluids such as hydrofluoric or hydrochloric acid, oxygen, or any other reactive liquid or gas as may be desired. The reactive fluid suppliesneed not supply the same reactive fluid and preferably each supply a different reactive fluid. There may be more than one inert fluid supplyand more than two reactive fluid suppliesdepending on processing requirements. In yet other embodiments, the inert fluid supplymay supply a chemically reactive fluid which is not chemically reactive with the reactive fluid supplies. In other words, mixing the fluid from the inert fluid supplywill result in no reaction with the fluid of the reactive fluid suppliesbut the fluid from the inert fluid supplywill react with other fluids or materials.

2000 100 400 500 1100 400 500 1300 1200 100 400 500 100 400 100 500 100 1010 500 The processing systemcomprises a plurality of apparatuses for controlling flow, an outlet manifold, a vent manifold, and a plurality of valvesused to selectively isolate the outlet and vent manifolds,from a processing chamberand a vacuum source. In yet other implementations, some of the apparatuses for controlling flowmay be exclusively coupled to the outlet manifoldor the vent manifold. Thus, it is conceived that one of the apparatuses for controlling flowmay exclusively be coupled to the outlet manifold. It is also conceived that one of the apparatuses for controlling flowmay be exclusively coupled to the vent manifold. In some implementations, the apparatus for controlling flowwhich supplies an inert fluid from the inert fluid supplymay be exclusively coupled to the vent manifold.

15 FIG. 2000 2000 2000 1011 104 100 2000 1010 104 100 100 110 400 190 500 400 1300 500 1200 illustrates a method of controlling fluid flow using the processing system. First, the processing systemis provided, the processing systemconfigured to supply a first process fluid from a first reactive fluid supplyto an inletof a first apparatus for controlling flow. The processing systemis also configured to supply a second process fluid from a first inert fluid supplyto an inletof a second apparatus for controlling flow. Each of the first and second apparatuseshave an outletfluidly coupled to the outlet manifoldand a bleed portfluidly coupled to the vent manifold. The outlet manifoldis fluidly coupled to the processing chamberwhile the vent manifoldis fluidly coupled to the vacuum source. Preferably, the first process fluid is reactive while the second process fluid is inert.

2000 1300 100 104 110 400 1300 1300 100 100 190 500 1200 Subsequent to providing the processing system, the first process fluid is delivered to the processing chamber. The first process fluid is flowed through the first apparatus for controlling flowfrom the inletto the outlet, through the outlet manifold, and on to the processing chamber. Optionally, the first process fluid may be flowed at a known mass or volume flow rate to the processing chamberdepending on the process requirements and the capabilities of the apparatus for controlling flow. Then, the first process fluid is vented from the first apparatus for controlling flowvia the bleed portto the vent manifoldand on to the vacuum source.

500 500 250 The first process fluid is preferably vented at a first flow rate to maintain a concentration of the first process fluid within the vent manifold. Preferably, the first flow rate is below a first threshold and the concentration is below a second threshold. The first and second thresholds are selected to minimize risk of undesired reactions of the first process fluid with other process fluids within the vent manifold. These values may be stored in a memory of the controllerand selected by a user such as a process engineer or technician.

110 1300 190 1200 1300 1200 1300 1200 1300 1200 110 190 Optionally, the first process fluid may be flowed through the outletto the processing chamberprior to venting the process fluid through the bleed portto the vacuum source. Optionally, the first process fluid may be flowed to the processing chamberconcurrently with venting to the vacuum sourceor the process fluid may be flowed to the process chamberonly until it is vented to the vacuum source. Thus, the first process fluid may be delivered to the processing chamberprior to or concurrently with venting to the vacuum source. The flow rate through the outletneed not be equal to the flow rate through the bleed port.

500 500 190 100 500 500 110 1300 500 Subsequent to venting of the first process fluid to the vent manifold, the second process fluid may be vented to the vacuum manifoldvia the bleed portof the second apparatus for controlling flow. Thus, the second process fluid is an inert fluid which serves as a buffer between the first process fluid within the vent manifoldand any subsequent process fluids. The second process fluid may be flowed at a controlled flow rate to achieve a target concentration of the first process fluid within the vent manifoldor it may simply be flowed at an arbitrary flow rate to dilute the first process fluid. Finally, the flow of the first process fluid from the outletto the processing chamberis halted. This may be done prior to or subsequent to the flowing of the second process fluid into the vent manifold. The sequencing of the delivery of the first process fluid, venting of the first process fluid, venting of the second process fluid, and halting of the first process fluid can be varied. Venting and delivery can occur simultaneously if so desired.

2000 1011 104 100 110 100 1300 190 100 500 In yet further steps, the processing systemmay comprise a third process fluid supplied from a second reactive fluid supplyto an inletof a third apparatus for controlling flow. Preferably, the third process fluid is reactive. Optionally, the third process fluid is flowed from the outletof the third apparatus for controlling flowto the processing chamber. Either concurrently or subsequently, the third process fluid may be flowed out of the bleed portof the third apparatus for controlling flowto the vent manifold.

500 500 250 The third process fluid is preferably vented at a second flow rate to maintain a concentration of the third process fluid within the vent manifold. Preferably, the second flow rate is below a third threshold and the concentration is below a fourth threshold. The third and fourth thresholds are selected to minimize risk of undesired reactions of the third process fluid with other process fluids within the vent manifold. These values may be stored in a memory of the controllerand selected by a user such as a process engineer or technician.

16 FIG. 16 FIG. 15 FIG. 2000 2000 1011 100 2000 1010 100 500 190 100 Turning to, another method of controlling flow is illustrated. In the method of, the processing systemis provided. As with, the processing systemcomprises a first reactive fluid supplycoupled to a first apparatus for controlling flowand configured to supply a first process fluid. The processing systemalso comprises a first inert fluid supplycoupled to a second apparatus for controlling flowand configured to supply a first process fluid. Preferably, the first process fluid is reactive while the second process fluid is inert as above. The first process fluid is delivered to the vent manifoldvia the bleed portof the first apparatus for controlling flow. The first process fluid is delivered at a first flow rate.

110 1300 500 1300 500 500 250 Then, the first process fluid is delivered to the outletof the first apparatus for controlling flow and then on to the processing chamber. The first process fluid may be simultaneously or sequentially delivered to the vent manifoldand the processing chamber. The first process fluid is preferably vented at the first flow rate to maintain a concentration of the first process fluid within the vent manifold. Preferably, the first flow rate is below a first threshold and the concentration is below a second threshold. The first and second thresholds are selected to minimize risk of undesired reactions of the first process fluid with other process fluids within the vent manifold. These values may be stored in a memory of the controllerand selected by a user such as a process engineer or technician.

1300 500 190 500 500 1300 1300 1300 1300 Thus, it is clear that, depending on the process requirements and other considerations, the first process fluid may be flowed to the processing chamberbefore, after, or concurrently with venting to the vent manifold. Furthermore, the second process fluid may be delivered to the bleed portof the second apparatus for controlling flow and then on to the vent manifoldeither concurrently or subsequently to the delivery of the first process fluid to the vent manifold. The delivery of the second process fluid occurs independently of the delivery of the first process fluid to the processing chamberand may also occur concurrently with the delivery of the first process fluid to the processing chamberor after delivery of the first process fluid to the processing chamber. Finally, the flow of the first process fluid to the processing chamberis halted.

1011 104 100 110 100 1300 190 100 500 Further optionally, a third process fluid may be delivered from a second reactive fluid supplyto an inletof a third apparatus for controlling flow. Preferably, the third process fluid is reactive. Optionally, the third process fluid is flowed from the outletof the third apparatus for controlling flowto the processing chamber. Either concurrently or subsequently, the third process fluid may be flowed out of the bleed portof the third apparatus for controlling flowto the vent manifold.

500 500 250 The third process fluid is preferably vented at a second flow rate to maintain a concentration of the third process fluid within the vent manifold. Preferably, the second flow rate is below a third threshold and the concentration is below a fourth threshold. The third and fourth thresholds are selected to minimize risk of undesired reactions of the third process fluid with other process fluids within the vent manifold. These values may be stored in a memory of the controllerand selected by a user such as a process engineer or technician.

500 As is apparent, it is conceived that the concentration and flow rate of each of the process fluids may be controlled below their respective thresholds so as to ensure that process fluids do not interact within the vent manifold. Inert process fluids may be used as buffers or the inert process fluids may be omitted. Optionally, the respective concentrations and flow rates of the reactive process fluids may be controlled below their respective thresholds and the inert process fluid omitted.

While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques. It is to be understood that other embodiments may be utilized, and structural and functional modifications may be made without departing from the scope of the present invention. Thus, the spirit and scope of the invention should be construed broadly as set forth in the appended claims.

Exemplary Claims:

Exemplary Claim 1: A method of controlling fluid flow comprising: providing a processing system comprising a first fluid supply configured to supply a first process fluid, the first fluid supply fluidly coupled to an inlet of a first apparatus for controlling flow, and a second fluid supply configured to supply a second process fluid, the second fluid supply fluidly coupled to a second apparatus for controlling flow; delivering the first process fluid to a processing chamber fluidly coupled to an outlet of the first apparatus for controlling flow; and venting the first process fluid to a vent manifold fluidly coupled to a bleed port of the first apparatus for controlling flow at a first flow rate which is less than a first threshold.

Exemplary Claim 2: The method of exemplary claim 1 wherein the step of venting further comprises venting the second process fluid to the vent manifold via a bleed port of the second apparatus for controlling flow.

Exemplary Claim 3: The method of exemplary claim 2 wherein the first process fluid is reactive and the second process fluid is inert.

3 Exemplary Claim 4: The method of exemplary claim 2 or exemplary claimwherein the second process fluid is an inert gas.

Exemplary Claim 5: The method of any one of exemplary claims 2 to 4 wherein the second apparatus for controlling flow vents the second process fluid simultaneously with the venting of the first process fluid.

Exemplary Claim 6: The method of any one of exemplary claims 2 to 5 wherein the second apparatus for controlling flow vents the second process fluid at a second flow rate to control a concentration of the first process fluid below a second threshold.

Exemplary Claim 7: The method of any one of exemplary claims 1 to 7 wherein the step of venting is performed subsequent to the step of delivering.

Exemplary Claim 8: The method of any one of exemplary claims 1 to 7 wherein the first apparatus for controlling flow comprises a flow path extending from the inlet to the outlet and the bleed port, a first proportional valve fluidly coupled to the flow path between the inlet and the bleed port and a second proportional valve fluidly coupled to the flow path between the first proportional valve and the bleed port.

Exemplary Claim 9: The method of exemplary claim 8 wherein the second proportional valve is configured to vent the first process fluid at the first flow rate.

Exemplary Claim 10: The method of any one of exemplary claims 1 to 9 wherein the processing system further comprises a controller comprising a memory, the memory of the controller storing the first threshold.

Exemplary Claim 11: A method of controlling fluid flow comprising: providing a processing system comprising a first fluid supply configured to supply a first process fluid, the first fluid supply fluidly coupled to an inlet of a first apparatus for controlling flow, and a second fluid supply configured to supply a second process fluid, the second fluid supply fluidly coupled to a second apparatus for controlling flow; delivering the first process fluid to a processing chamber fluidly coupled to an outlet of the first apparatus for controlling flow; and venting the first process fluid to a vent manifold fluidly coupled to a bleed port of the first apparatus for controlling flow at a first flow rate and simultaneously venting the second process fluid to the vent manifold fluidly coupled to a bleed port of the second apparatus for controlling flow at a second flow rate to control a concentration of the first process fluid within the vent manifold below a second threshold.

Exemplary Claim 12: The method of exemplary claim 11 wherein the first flow rate is less than a first threshold.

Exemplary Claim 13: The method of exemplary claim 11 or exemplary claim 12 wherein the first process fluid is reactive and the second process fluid is inert.

Exemplary Claim 14: The method of any one of exemplary claims 11 to 13 wherein the second process fluid is an inert gas.

Exemplary Claim 15: The method of any one of exemplary claims 11 to 14 wherein the step of venting is performed subsequent to the step of delivering.

Exemplary Claim 16: The method of any one of exemplary claims 11 to 15 wherein the first apparatus for controlling flow comprises a flow path extending from the inlet to the outlet and the bleed port, a first proportional valve fluidly coupled to the flow path between the inlet and the bleed port and a second proportional valve fluidly coupled to the flow path between the first proportional valve and the bleed port.

Exemplary Claim 17: The method of exemplary claim 16 wherein the second proportional valve is configured to vent the first process fluid at the first flow rate.

Exemplary Claim 18: The method of any one of exemplary claims 11 to 17 wherein the processing system further comprises a controller comprising a memory, the memory of the controller storing the second threshold.

Exemplary Claim 19: A method of controlling fluid flow comprising: providing a processing system comprising a first fluid supply configured to supply a first process fluid, the first fluid supply fluidly coupled to an inlet of a first apparatus for controlling flow, and a second fluid supply configured to supply a second process fluid, the second fluid supply fluidly coupled to a second apparatus for controlling flow; venting the first process fluid to a vent manifold fluidly coupled to a bleed port of the first apparatus for controlling flow at a first flow rate, a concentration of the first process fluid within the vent manifold being below a second threshold; and delivering the first process fluid to a processing chamber fluidly coupled to an outlet of the first apparatus for controlling flow.

Exemplary Claim 20: The method of exemplary claim 19 wherein the step of venting further comprises venting the second process fluid to the vent manifold via a bleed port of the second apparatus for controlling flow.

Exemplary Claim 21: The method of exemplary claim 20 wherein the first process fluid is reactive and the second process fluid is inert.

21 Exemplary Claim 22: The method of exemplary claim 20 or exemplary claimwherein the second process fluid is an inert gas.

Exemplary Claim 23: The method of any one of exemplary claims 20 to 22 wherein the second apparatus for controlling flow vents the second process fluid simultaneously with the venting of the first process fluid.

Exemplary Claim 24: The method of any one of exemplary claims 20 to 23 wherein the second apparatus for controlling flow vents the second process fluid at a second flow rate to control a concentration of the first process fluid below a second threshold.

Exemplary Claim 25: The method of any one of exemplary claims 19 to 24 wherein the step of venting is performed prior to the step of delivering.

Exemplary Claim 26: The method of any one of exemplary claims 19 to 25 wherein the first apparatus for controlling flow comprises a flow path extending from the inlet to the outlet and the bleed port, a first proportional valve fluidly coupled to the flow path between the inlet and the bleed port and a second proportional valve fluidly coupled to the flow path between the first proportional valve and the bleed port.

Exemplary Claim 27: The method of exemplary claim 26 wherein the second proportional valve is configured to vent the first process fluid at the first flow rate.

Exemplary Claim 28: The method of any one of exemplary claims 19 to 27 wherein the processing system further comprises a controller comprising a memory, the memory of the controller storing the first threshold.